queue_element
queue_element *head;
queue_element *tail;
queue_element *elem = (queue_element *)e;
queue_element *temp, *last = NULL;
temp = (queue_element *)q->head;
q->head = (queue_element*)temp->next;
temp = (queue_element*)temp->next;
queue_element *elem = (queue_element *)e;
queue_element *elem;
q->head = (queue_element*)q->head->next;